Parkinson's disease (PD) is a common degenerative neurological disease, affecting approximately 1 million Americans. Advances in the treatment and management of PD over the past ten years have increasingly required general neurologists to seek advice from Movement Disorders specialists in order to optimize PD patient care. With advances in the understanding of the pathophysiology PD, new strategies for slowing the course of PD are emerging. As these therapies have begun to move to clinical trials, patient access to these trials has been and will likely continue to be primarily through PD centers. We have assembled a network of PD specialists in or near Long Island, NY with a combination of practical experience in the management of PD, extensive clinical trial experience, and clinical research excellence related to the development of imaging methods for assessing therapies for PD. With this combination of PD clinical trial and research experience and a very broad population base, we are uniquely positioned to achieve the following Specific Aims: 1) To participate successfully in the planned large-scale simple neuroprotective clinical trial for PD. At North Shore University Hospital (NSUH) we have a long track record of successful completion of clinical trials for PD and of recruitment for clinical research; and 2) To provide expertise regarding potential neuroimaging markers for the planned clinical trial. The functional imaging laboratory at NSUH has focused on the assessment of therapies for PD. Drs. Feigin and Eidelberg are currently funded by NINDS to study issues directly related to the assessment of potential neuroprotective agents for PD and therefore have a unique perspective that may be of benefit for the planning of the future clinical trial. To support our contention that we can successfully achieve these Specific Aims, this application will focus on five areas: 1) The demographics of our catchment area; 2) A description of our current PD patient population and our multidisciplinary PD center; 3) Plans to further enhance recruitment for the planned clinical trial; 4) The experience of our center personnel with all aspects of clinical trial conduct both through multicenter consortiums and independently; and 5) A brief description of our imaging studies of therapies for PD.